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Thesis defences

PhD Oral Exam - Sinda Kassab, Economics

Three Essays on R&D Competition with Spillovers: Theory and Experiment

Date & time
Tuesday, May 21, 2024
10 a.m. – 1 p.m.

This event is free


School of Graduate Studies


Nadeem Butt


Henry F. Hall Building
1455 De Maisonneuve Blvd. W.
Room 1154

Wheel chair accessible


When studying for a doctoral degree (PhD), candidates submit a thesis that provides a critical review of the current state of knowledge of the thesis subject as well as the student’s own contributions to the subject. The distinguishing criterion of doctoral graduate research is a significant and original contribution to knowledge.

Once accepted, the candidate presents the thesis orally. This oral exam is open to the public.


This thesis consists of three chapters. The first chapter “Dynamic Patent Races with Absorptive Capacity: An Experimental Investigation on R&D Behavior” reports a laboratory experiment on dynamic patent races in an indefinite horizon with complete information. In a competitive environment, we analyze the R&D investment behavior of the players who are randomly and anonymously paired with one another in each sequence. In the experiment, we vary subjects’ initial positions in each race in order to examine how the players react to a leader/follower or symmetric/asymmetric position as well as the distance between the initial knowledge stock and the target. Our results show that the individual average effort is highest for the players who are in a tie position, second highest for the leaders and lowest for the followers. Starting as a follower (leader) leads to a lower (higher) chance of winning the race, and the spillovers in the previous round significantly increase the players’ investment in the current round. By comparing the first and second half of the session, we observe an overall learning effect on the pure-strategy equilibrium play, but efficiency loss remains throughout the session. 

The second chapter “Government Subsidy and R&D Quality Investment” investigates the effect of R&D subsidies on the innovating firms’ quality investment choices and profits as well as social welfare in a duopoly market with product substitutability, demand spillovers and consumers’ quality sensitivity. Taking the non-cooperative and cooperative scenarios into account, respectively, the optimal R&D subsidy levels are solved in a way to maximize the social welfare. Compared with the no-subsidy case, the firms are better off under the R&D subsidy policy. Furthermore, it is always socially beneficial to subsidize the non-cooperative regime or the cooperative agreement in which the firms coordinate their R&D activities while remain competitive in the production stage.

The third chapter “R&D Investment under Symmetric and Asymmetric Absorptive Capacity” considers a two-stage strategic R&D model in a duopoly market. In the first stage, two firms decide simultaneously whether to compete or to cooperate by choosing the level of R&D investment that might decrease the investing firm’s production cost and the rival’s cost through the absorptive capacity. In the second stage, after observing the R&D outcome, the two firms play the classical Cournot in order to maximize their own profits. I consider two dimensions of variations of the model: whether the R&D technology is stochastic or deterministic, and whether the absorptive capacity of the two firms is symmetric or asymmetric. Under the stochastic R&D technology with low or high symmetric absorptive capacity, I find that the difference between the optimal R&D expenditures under defection and those under cooperation becomes larger as the probability of success increases. Regardless of whether the absorptive capacities of the two firms are same or different, except at the critical threshold, the R&D outcomes always align with the prisoner's dilemma situation.

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